To obtain a clear image at half-size photographing too.

Notches 47a and 47b and recessed parts 47c and 47d are formed in a cam 47 constituting a shutter device at intervals of 180°, respectively. The cam 47 is engaged with a sprocket 49, and when a photographic film 20 is wound by operating a take-up knob 23, the cam 47 is rotated integrally with the sprocket 49. Four pieces of perforations 25 formed in the photographic film 20 are fed, the notches of the cam are rotated by 180° and the catch 46b of a locking lever 46 enters the notch of the cam. In this case, a film supporting surface arranged on a back cover is formed in the width direction of the photographic film 20 and also so that the photographic film 20 may project backward, then, the object image hardly affected by the curvature of image and chromatic aberration, etc., is obtained.